UPSTREAM: x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

The common/64/x32 distinction has no effect other than
determining which kernels actually support the syscall.  Move
the logic into syscalltbl.sh.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 32324ce15ea8cb4c8acc28acb2fd36fabf73e9db)

Bug: 119769499
Change-Id: Ib994586ac47f8f4cbc3f746492c2b47b22e03d39
Signed-off-by: Greg Hackmann <ghackmann@google.com>